Non-enzymatic sensing of hydrogen peroxide using a glassy carbon electrode modified with a nanocomposite made from carbon nanotubes and molybdenum disulfide

We report on a non-enzymatic electrochemical sensing strategy for ultrasensitive detection of hydrogen peroxide (H₂O₂) at nanomolar levels. A glassy carbon electrode (GCE) was modified with a hybrid material consisting of multiwalled carbon nanotubes (CNT) and molybdenum disulfide (MoS₂). Transmission electron microscopy and Raman spectroscopy were employed to characterize the hybrid nanostructures. GCEs modified with carbon nanotubes, or nanoscaled MoS₂, or with the CNT-MoS₂ hybrid were investigated with respect to sensing H₂O₂, and this revealed that the GCE modified with the CNT-MoS₂ hybrid performed best and resulted in a limit of detection as low as 5.0 nM. A repeatability and intermediate precision of 9 % was accomplished. The method was applied to determine H₂O₂ in spiked sterilized milk and gave satisfactory results. (author)